Immunological methods are to be applied to studies on addictive drugs. The use of hemagglutination-inhibition tests for the diagnosis of drug abuse is to be extended from heroin and methadone to cocaine, barbiturates and amphetamines. Solid phase immunoadsorbants will be employed to concentrate and purify drug metabolites from urine, and to prepare antibodies of restricted specificities. Labeled antibodies are to be used in tracing of the drugs on the organ, tissue, cell and subcellular levels. The significance of actively or passively acquired immunity in the reaction to specific drugs is to be further investigated.